Bill McGuire, a member of the Government's Natural Hazard Working Group, warns
the Telegraph Hay Festival of an age of "geological havoc".

Global warming is causing earthquakes and giant landslides, and could bring about an age of “geological havoc” including “volcano storms” and tsunamis, a top academic told the Telegraph Hay Festival today.

Bill McGuire, Professor of Geophysical and Climate Hazards at University College, London - and a member of the Government's Natural Hazard Working Group, established after the 2004 tsunami – said: “climate change is already beginning to affect the solid earth. We are seeing the effects today”.

The geological disasters are caused by melting ice cover and rising sea levels, Prof McGuire explained. Ice sheets weigh down the ground beneath them, which rises as they disappear, causing geological stresses: the meltwater runs into the oceans, which then become heavier an depress the seabed, with similar results.

Research shows that this happened at the end of the last ice-age, when Scandinavia, for example, “bounced back up by 300 metres”, suffering earthquakes that measured 8 on the Richter scale. In all, 52 million cubic kilometers of water poured into the oceans, raising sea levels by 130 metres, and causing more quakes. One caused a huge submarine landslide of sediment off Norway's West coast, which triggered a tsunami that hit Scotland and the Shetlands.

At much the same time Iceland suffered a 1,500 year long “volcano storm”, with the number of eruptions increasing more than thirty fold, when its 1 km thick icesheet thinned. The weight of the ice had prevented active volcanos underneath it from releasing magma: they blew when the pressure was released.

Related Articles

Prof McGuire – who was also a member of the Science Advisory Group in Emergencies that addressed the chaos caused by Eyjafjallajökull eruption in 2010 – said that the speed of today's climate change was unprecedented in the Earth's history. There was already more carbon dioxide in the atmosphere than at any time in the last 15 million years and melting of the Greenland ice sheet would become irreversible in ten to thirty years if present trends continued.

He said: “We are going to get climate chaos. Are we going to have geological havoc added to it? Climate change is already driving more earthquakes and giant landslides in some parts of the world.”

He described Alaska, where average winter temperatures have already risen by three degrees centigrade in the last half century,as “the canary in the cage”. Earthquakes and seismic shocks have increased there over recent decades as ice sheets have thinned,and landslides have become more frequent as permafrost biding rock to mountainsides has thawed. There has also been a similar increase in landslides in the Alps, the Caucuses and in New Zealand.

Most recent earthquakes, he added,had been caused by conventional geological activity, without any contribution from climate change, but global warming was likely to make things worse in future.